Rustic-mode is not loaded automatically on rustlings exercises

[picdc]

Using rustilings (https://github.com/rust-lang/rustlings)

• cargo build && cargo run -- lsp (builds the watcher for the exercises and the lsp configuration for it)

emacs exercises/variables/variables1.rs

Rustic mode is not used, only rust-mode (with no LSP). M-x rustic-mode of course works, and the LSP activates correctly.